Refrigerator condensing unit cooler



Oct. 20, 1953 J, DY 2,655,795

REFRIGERATOR CONDENSING UNIT COOLER Filed Jan. 2, 1952 Patented Oct. 20,1953 REFRIGERATOR CONDENSING UNIT COOLER John Dyer, Tucson, Ariz.

Application January 2, 1952, Serial No. 264,562

2 Claims.

denser and a liquid receiver all contained within an insulated casetogether with control thermostats, and arranged so that if thetemperature drops below a certain point the heat developed by thecompressor will be confined and retained within the case so that thetemperature of the condenser will not drop below that of the area to becooled and the pressure drop across the metering valve will remainwithin an efficient operating range;

Another object is to provide evaporative cooling mechanism within saidcase so that when the temperature rises above a predetermined level theair passing over the condenser will be cooled by evaporation of water sothat its actual temperature as it contacts the condenser coils will belower than the outside air which would otherwise be forced over thecondenser coils;

Another object is to provide an insulated case for an air cooledrefrigeration unit which has an air inlet provided with an evaporativecooler pad over which water may be flowed and through which air may bedrawn into the case, and an exhaust stack having a fan adapted to forceair therefrom; the case being arranged generally to v maintain atemperature suitable for the efficient operation of the refrigerationunit.

Other objects will appear hereinafter.

I attain the foregoing objects by means of the devices and constructionshown in the accompanying drawing in which- Figure 1 is an end view ofthe refrigeration unit case;

Figure 2, a longitudinal sectional view thereof taken substantially online 2-2 of Figure 1; and

Figure 3, a diagrammatic representation of a compartment to be cooled.

Similar numerals refer to similar parts in the different views.

The case 2 is rectangular and has bottom 3, top 4, side walls 5, as wellas one end wall 6, composed of insulating material I, such as cork orglass wool, confined between outer and inner metal sheets 9 and Irespectively. The cut lines XX in Figures 2 and 3 represent anindeterminate distance from case 2 to compartment 43.

The case is divided interiorly by a partition l2 into an outercompartment l4 and an inner compartment l5.

Refrigeration apparatus is disposed within compartment I5 and includescompressor I6 driven by motor l1, condenser I8, receiver [9, andthermostat control switch 20. The condenser is positioned in an openingin partition 12. Motor I! has a fan I8 adapted to draw air through thecondenser from outer compartment l4 to inner compartment [5. This airthen exhausts through ventilator 23. When desired this is accelerated byelectrically driven fan l9. Fluid refrigerant leaves the receiverthrough pipe 20 and goes to the evaporator 40 in the compartment 43which is to be cooled through expansion or metering valve 42. Thereafterexpanded refrigerant is drawn through pipe 2i to the compressor.

The open end 8 of case 2 is provided with an evaporative pad 22 composedof fibrous material 23, such as excelsior or the like, which is confinedbetween screens 24 and 25. A sump 263 is in the bottom of the case part[4 and water is pumped from this by an electric motor-driven pump 2'!and delivered into perforated trough 28 at the top of pad 22. This Watertrickles down through the pad and returns to the sump. Fresh water maybe added when the water in the sump falls below a predetermined level byoperation of float valve 30 which is in water supply line 3|. Air isdrawn through pad 22 so long as hinged louver slats 33 are open, asshown in Figure 2. These slats are operated in unison by rod 34 andthis, in turn, by bellows 35 which is expanded or contracted by gas inbulb 36, which may be either within or outside of case 2. When thetemperature within the box exceeds a predetermined temperature, say 66F., the bellows 35 opens the slats. So long as the temperature withinthe box stays below the pump 21, controlled by electrical thermostat 20,does not operate, and fan Is merely draws outside air through the caseand over the condenser. When the temperature rises above 85 pump 21starts and pumps water over pad 22 and exhaust fan 19 starts.Evaporation of water in this pad effectively reduces the temperature ofthe air circulating over the condenser and thus increases the efficiencyof the condensing unit.

Bulb 36 and bellows 35 may be supplanted by a bi-metal strip or anyother heat sensitive control mechanism desired.

I have determined by test that with outside air temperatures as high asF., the efiective tem-- perature within the case 2 will not run over 88F. The temperature differential between the receiver and the evaporatoris thus kept within an efficient range, and there is less power consumedby motor H. The small amount of power consumed by fan motor [9, andmotor driven pump 21 is more than offset by the saving in power consumedby compressor motor l7. With the more effective pressure differentialbetween the interior of case 2 and the compartment to be cooled lessrunning time per unit of time (hour or day) is required to keep therequired amount of refrigerant condensed in receiver 19.

In cold weather gas in bulb 36 contracts and bellows 35 contracts so asto close louver slats 33. Pump 2"! andZ-motor: l9 are'shutcfiby thermostat The heat generated by" compressor I6 and motor I! is sufiicientwhen conserved by the insulated case 2 to keep the temperature withinthe case above that of the compartment to be cooled. Thus there is atemperature drop between the condenser I8 and the evaporator 40'sufiicient to keep the expansion valve'fl opem Otherwise, I have found,that-when the temperature of the compressor unit drops to or below thetemperature where the evaporator isposi; tioned the pressure in thecondenser becomes so low relative to-that-inithe evaporator that'theexpansion valve does notoperate and requires servicing.

In commercial installations the capacity-of the device is determined bythe expansion or -metering valve. This is set or selected-to provide theresults required, under averageconditions, with a certain pressure dropacrosa-the-valve. The pressure drop ismaintainedibythe differencebetween the suction orintake pressure. oi -the compressor and the outputorhead pressure. Assuming the temperatureto be maintained by theevaporator to-be 40 FL, then when-outside air temperaturesare high, ,say85 -F.,,-there-cou1d be a head pressure of L35 pounds per square inch,and a suction pressure of 251 pounds per square inch, resulting in a 1pressure drop ofr 110 pounds per square inch which would operate throughthe expansion valve with good efiiciency. However, with outside air at409 EL, thev head pressure might well be 72 poundsper square inch whilethe suction pressure. would-be-only, 23 pounds per square inch,resulting in a-pressure drop of only 49 poundsper square-inch. Thiswould be inefiicientwith the same metering valve. Since commercialrefrigeration here concerned, are for the-most part, installedroutsideof heated habitations they are subjectedtofiuctuations of the weatherincluding the-temperature changes abovementioned; Thedevicaheredisclosed provides a means for;- overcoming; the inefficiencies caused.bythese. weather. changes and automatically compensatesv for: them::and.

minimizes the eifects of temperature extremes.

Thus, I have provided astructureand arrangement of partswhich-greatelyadds to-the efficiency of refrigeratorcompressor unitinstallations, particularly in climatessuch asencountered insouthwestern portions :of theeUnited States where the higher summertemperatures range from- 100 F. to LZOff E HandlQ er. wintertemperatures range from 20 to 40 F.-

l. A refrigerator condensing, unit comprising an insulated case, anintermediateipartition. dividing the interior into an outer compartmentand an inner compartment; a-condenserypositioned in an opening in saidpartition, the said outer compartment being provided with an inletopening enclosing a refrigerating evaporating pad, a water sump and amotor drawn pump for pumping water on to said pad and a shutter forclosing said inlet opening; said inner compartment being provided withan outlet opening, a compressor, a receiver and fans for drawing airfrom said-outer compartment:- and: circulating it therethrough and:forcingdt out of said outlet opening, and a thermostat mechanism forcontrolling the operation of said circulating fans,

said pump motor for moistening said evaporative padj'and'said shutter,whereby when the temperature within the case rises above apredetermined: degree, said fans will operate, said pump will pump waterto moisten said evaporative pad 'and'said 'shutters will open admittingair into said-outer compartment through said evaporating pad and forcingit over the surface of said condenser;v said fans operating tocirculateair within said' insulated case when the temperature within-itfalls below a predetermined degree.

2; In a refrigeration mechanism including. a compressor, a 'conderisenfareceiver, an expansion valve'andan evaporatorina compartment to becooled;jthe combinationtherewith of. an insulatedcase having apartition, including said condensenjdividing the iiiterior into an outercompartment and 'aninner, compartment,. said outer compartment havingIaninleto'pening ineluding an evaporating, refrigerating pad, a watersumpdn the-bottom, a motor drive'nipum'p for circulating water fromsaidsum'p, over said pad,,and-a normally, closedshutter operative byheatsens'itivet. mechanism to opie'n when the temperatureoutsidesaidcase exceeds a predetermined degree; I said inner compartment?enclosing said compressor andreceiver, having an outlet ventprovidedwithlafan driven bya motor and a thermostat connected to saidevaporating pad, pump motor andjsaid outlet vent fan motorsc that whenthe temperature-within. said "case'ex' ceeds I a predetermined degreeSaid" motors; O'DBI' ate' to producerefrigeration by; evaporation andforce air? cooled byf"'sair1evaporating pad over said condensery said;compressorliaving' av fan adapted'to: draw air from said outer'com'pjart ment into, saidinneri compartment and; force it out of" saidioutlet. vent; and to circulate: air within'said' case'wnenisaidshutterisclosed;

JOHN "DYEBLJ References Cited in meme-or thispatent

